Pen point



30 Thus, in accordance with the present invention, sentially, be rinsedeither in pure water or in a 30 Patented a. 19, 1937 o 2,096,434

UNIT-ED STATES PATENT" OFFICE PEN POINT Hiram Stanhope Lukens,Philadelphia, Pa., as- Signor to C.'Howard Hunt Pen Company, Camden, N.J., a corporation of New Jersey No Drawing. Application October 17,1935,

Serial No. 45,438

1 Claim; (Cl. 120109) This invention relates to an improved pen point.general the solution may range in acidity fIOm a The invention isparticularly concerned with the point approximating neutrality to apoint at production of pen points of the type comprising which thedeposit noticeably loses adherence. a base composed of a chromium alloysteel having A suitable platinum plating solution may be 5 anelectrolytically-deposited gold plate thereon, made up of the followingingredients in the apwhereby to secure an article which is not onlyproximate proportions indicated: highly acid resistant but. which isfurther inex- To each gallon of water addpensive as compared with solidgold pens.

In considering some of the objects of the nveng i ggfi i gg figg 10 tionit is first pointed out that heretofore it has Sodium c 10 been proposedto apply a gold plate to a chrom um p p oun es alloy steel pen point byimmersing the pen in a A suitable rhodium solution may be made up 7plating bath containing free hydrocyanic acid, a of the followingingredients in the approximate full disclosure of such a processappearing in my proportions indicated: 'copending application Serial No.21,190, filed May To each gallon of water add- 15 Issued May 1936 asPatent Rhodium sulphate 8 grams In accordance with the presentinvention, the The solution should also contain a slight pen is producedby first depositing a layer of amount of free sulphuric acid. highlyacid resistant metal such as platinum or Regardless of which solution isbeing employed, 2O

rhodium, onv top of which is deposited a layer of I prefer to proceed asfollows: goldin order to secure the desired gold surface The pens arefirst treated with hydrochloric and appearance. I acid in order todissolve the oxide film which nor- I have found that certain metals,such as platimally forms on the surface of chromium alloy mum andrhodium, may be deposited on a chrosteels. This may be done by dippingthe pens in 25 'mium alloy steel (when following the procedure arelatively concentrated hydrochloric acid soluhereinafter more fullydiscussed) without the use tio-n containing, for example, from about 25%to of free hydrocyanic acid which, of course, is difiiabout 50%hydrochloric acid. cult and dangerous to handle. Following this the pensmay, although not esan under-coating of a metal is first applied to thedilute hydrochloric acid rinse containing from p n, the i rating beingcapable of being about 10% to about 15% hydrochloric acid. depositedwithout the use of free hydrooyanic Whether or not the washing step isemployed, the acid and further having such characteristics as to pensshould very promptly be placed in the plat- .make it highly acidresistant or corrosion proof, ing solution, the rapidity of transferfrom one this being of importance because of the porosity bath toanother being of importance in order to of the gold plating applied asthe outer coat r avoid re-formation of the oxide film.

upon wear thereof to expose the metal of the base, I h further found t tthe cathode connec.

and in order to resist attack by acid and other tio h d b applied t tpens prior corroding ingredients frequently found in o mersion in theplating bath. If this is not done, 40 mercial inks. the deposit is notadherent, the reason for this In practicing the invention I prefer to PY possibly being that some constituent of the alloy as the base o the pn, a so-called stainless steel being plated is electropositive withreference to which ay be C p for p 0 the platinum or rhodium. Underthese circum- 5 chromium, 8% nickel and the balance iron. I stances animmersion deposit which is not highly p f r t us a alloy also nta g a t/z% adherent may therefore be produced before the molybdenum, this beingespecially effective in current is passed through the solution and theresisting corrosion under the influence of certain pens being plated. Onthe other hand it may conditions encountered in use. be that if the pensare immersed any appreciable 5 As to the nature of the process it ispointed interval of time prior to the application of the out that I havefound that the plating solution current, the solution would have atendency to should have arelatively low hydrogen ion concen reoxidizethe surface of the articles before the tration. In other words, thissolution should deposit is made. This condition might be aggrapreferablybe slightly acid, although the condition vated when employing platingsolutions approx-L 5 of the solution, as to acidity, is not critical. Inmating neutrality.

In any event, the most adherent deposit is secured by completing thecathode connection prior to immersion of the pens in the platingsolution.

Following this plating operation, the pens are then placed in a goldplating solution which may be of the usual cyanide type, prepared, forexample, in accordance with the following:

To each gallon of water add Sodium gold cyanide ounce Sodium cyanide 2ounces In accordance with the foregoing, it will be seen that theinvention provides for the production of a relatively inexpensive penhaving gold surface and appearance which pen is at the same time highlyacid resistant because of the nature of the materials employed and whichpen may further be produced without employing free hydrocyanic acid inany plating bath.

While I have referred to an under-coating of platinum in the appendedclaims, it is to be understood that I intend to include within the scopeof my protection any metal which can be used equivalently. A metalsuitable for the undercoating of my invention should have the follow ingcharacteristics: (a) a high degree of corrosion resistance, (b should becapable of being deposited on a chromium alloy steel without the use offree hydrocyanic acid, and (c) be one upon which an adherent golddeposit may be secured, also without the use of free hydrocyanic acid.

I claim:

As an article of manufacture, a pen point'comprisingra base composed ofa chromium alloy steel, the pen having an adherentelectrolytically-deposited layer of platinum thereon and an adherentelectrolytically-deposited layer of gold on the platinum deposit.

I-IIRAM'S. LUKENS.

